If you are teaching your AAC (augmentative-alternative communication) users core vocabulary, then these 3 core words books - each of which focuses on negation in a phrase - are just what you need to expand their language.
Check out each listing separately by following these links:
Core Words Not here
Core Words Not This and Yuck
and Core Words Not Me and Are You
This bundle price is approximately 15% off of the price of buying the 3 books separately.
And check out the rest of my store for many more AAC implementation resources, free handouts, and more